Anderson Cooper 360

New Impeachment Witness Testimony Just Released Less Than 48 Hours Before Public Hearings Begin; Pentagon Official Corroborated Ukraine Aid Tied To Pres. Trump's Demand For Biden Investigation; Pentagon Official Testified There Was Concern Freeze On Ukraine Military Aid Might Be Illegal; Pentagon Official: "Alarm Bells" Were Coming From Ambassador Taylor About Aid Freeze to Ukraine; Adviser: WH Put Missile Order For Ukraine On Hold; Mulvaney Concerned About Angering Russia; Exclusive Excerpts From "Anonymous Book"; Exclusive Excerpts From "Anonymous" Book On Ukraine, Military Aid; Exclusive Excerpts From "Anonymous" Book On Ukraine; Exclusive Excerpts From "Anonymous" Book On Mulvaney; Exclusive Excerpts From "Anonymous" Book On Pres. Trump; Exclusive Excerpt From "Anonymous" Book: "Barely Believable" That Pres. Trump Wanted To Combat Corruption On Ukraine; Exclusive Excerpt From "Anonymous" Book Mulvaney's &qu